#include<stdio.h>
#include<string.h>
#include<unistd.h>
int main()
{
  printf("hello tzc\n");//stdout
  perror("perror:");//stderr

  fprintf(stdout,"stdout:hello tzc1\n");//1
  fprintf(stderr,"stderr:hello tzc2\n");//2
  //C语言库函数
  //printf("hello tzc1\n");
  //fprintf(stdout,"hello tzc2\n");
  //
  ////system函数
  //const char * str="hello tzc3\n";
  //write(1,str,strlen(str));
  //
  //fork();
  return 0;
}
